1. Field of the Invention
The present invention relates to a method and device for aligning a radar (radio detecting and ranging device) mount direction, and to a radar system. More specifically, the present invention relates to a radar device which enables easy and correct alignment of a radar mount direction and a transmission/receipt direction to be used for aligning the transmit/receive direction of the radar, as well as to a method of aligning a radar mount direction to be used for aligning the transmit/receive direction of the radar.
2. Description of the Related Art
An intervehicle distance warning system or adaptive cruise control, which employs a radar, has already been available as a driving support system. Some inter-vehicle warning systems determine a distance between vehicles from a time lag from the time a laser pulse is emitted forward until the time of receipt of the pulse having been transmitted from a reflector of a vehicle driving ahead (i.e., a reflection plate provided on a tail lamp of a vehicle). In this way, application of a radar technology and provision of a radar on a vehicle enable realization of a superior driving support system.
However, the following problem is encountered in mounting a radar device on a vehicle. For instance, when a radar is mounted on a vehicle as an inter-vehicle distance warning system, a radar device must be mounted so as to be able to capture the vehicle driving ahead without fail.
If the transmit/receive direction of the radar is aligned with an error of 0.8 degrees, the error is equivalent to a distance of 1.4 m in a case where the vehicle is driving ahead at a distance of about 100 m. Even when another vehicle is driving ahead of a vehicle equipped with an inter-vehicle distance warning system, a sensing area of the system may deviate from a traffic lane, thereby failing to capture the vehicle ahead or misidentify a vehicle driving on the opposite lane as a vehicle driving head of oneself.